Byakuren
An easy way to get Byakuren (the giant snake that attacks you when you cross the bridge in your Headquarters) is to have Levi (the magician) in your party and defeat him. Afterwards he will join your Star Of Destiny tablet.

Camos w/ Scarf
Get 20 Platinum Records.

Completion bonus
Successfully complete the game and save when prompted. Start a new game and select the cleared saved game file. You will begin with the money from your previous game, collected formations, your Party SP, collected Epics, inventory and storage items, and your Hero's name. Additionally, press L2 or Triangle to run faster.

Devil Girl Outfit
Get 8 Platinum Records.

Diamond Bracelet
Get 17 Platinum Records.

Easy money and armor
Once you recruit Subala, store all of your party items with Chuck. Then, play the fishing game against Subala at your headquarters. When you play the fishing game, sometimes you will catch "? Pot" and parts of fish bodies. Play the fishing game about five or six times (depending upon your skill). Go to the closest appraiser and get all of your "? Pots" appraised. You can then turn around and sell the pots to the appraiser for a significant profit. It is possible to make over 200,000 Potch in one trip. The fish body parts are armor that you can equip on a few characters. This is good armor to have fairly early in the game.

Enrique Character
Get 14 Platinum Records.

Flames Cowboy Hat
Get 13 Platinum Records.

FlatTop Cowboy Hat
Get 1 Platinum Records.

Garth Brooks - Friends in Low Places
Get 6 Platinum Records.

George
It is recommended that you do not level up George because you cannot use him in the final battle.

Glam jacket & Scarf, Vinyl Pants
Get 21 Platinum Records.

Glam Tower Hair, Glam Tux & Scarf
Get 9 Platinum Records.

Gym Shorts
Get 16 Platinum Records.

Handlebar Moustache
Get 15 Gold Records.

Hi-Top Hair, Star Glasses, Funk Coat
Get 19 Platinum Records.

Josephine
She is in Haud after the Battle Of Raftfleet (around there). You must have Lady Sialeeds in your party.

Junior Character
Get 20 Gold Records.

Lady Sialeeds
It is recommended that you do not level up Lady Sialeeds because you cannot use her in the final battle.

Liberty Spikes Hair, Punk Jacket
Get 18 Platinum Records.

Long Coat, Slacks, Motorcycle boots w/Socks
Get 12 Platinum Records.

Monique Character
Get 750,000 Total Points.

Muraad
He will be at every place where there is a large battle. Keep asking him until he joins at each of the places (such as Rainwall, Raftfleet, Lelcar, and Doorat).

Oboro
When you are in Rainwall you will need him to advance in the story. When you are done speaking with him, go to the inn and talk to Norden. When you are done following the next few scenes, wait until after the battle of Raftfleet. He will be there and you can ask him to join. Note: You should do the bar scene or he will be difficult to get.

Open Shirt
Get 7 Platinum Records.

Renaissance Outfit
Get 1,500,000 Total Points.

Retro Cowgirl Outfit
Get 250,000 Total Points.

Rocker Pants
Get 22 Platinum Records.

Rodeo Dude Outfit
Get 10 Gold Records.

Skip boat sailing scenes
When you sail on a boat to a location, press Triangle while sailing to skip the boat trip and arrive immediately at your destination.

Super character
The following setup will basically make your character immortal:

Equip four Eyeball Rings
Rune Slot 1: A Strike-Back Rune
Rune slot 2: Double Edge Sword (If the character has a 2nd Rune slot)
Rune slot 3: Drain Rune (If the character has a 3rd Rune slot)
This setup is not cheap, but it is possible to handle many Bosses solo with it. You may need to remove the Double Edge rune from some characters because they do not have a lot of HP. Go to the big hole near the rotating bridge. In the area before the ruins, the Eyeball Ring is commonly dropped.